mercurio.jpgMercury is the closest planet to the Sun, but surprisingly, not thehotest.
Mercury hasn't got an atmosphere, so any heat, the planet get from the Sun quckly escapes back into the space. Temperatures can still get as high as 427ºC which is 61 times hotter than the average temperature on the Earth! But because there is nothing to hold in the heat, Mercury can also reach temperatures as low as -173ºC, almost twice as cold as the lowest temperature ever recorded on the Earth. No atmosphere also means the planet doesn't have a sky! If you could visit Mercury, you would be able to see stars at daytime and the sun would look twice as big. Mercury is a smaller than Jupiter.